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1.
With the intensifying global efforts to eradicate wild polioviruses, policymakers face complex decisions related to achieving eradication and managing posteradication risks. These decisions and the expanding use of inactivated poliovirus vaccine (IPV) trigger renewed interest in poliovirus immunity, particularly the role of mucosal immunity in the transmission of polioviruses. Sustained high population immunity to poliovirus transmission represents a key prerequisite to eradication, but poliovirus immunity and transmission remain poorly understood despite decades of studies. In April 2010, the U.S. Centers for Disease Control and Prevention convened an international group of experts on poliovirus immunology and virology to review the literature relevant for modeling poliovirus transmission, develop a consensus about related uncertainties, and identify research needs. This article synthesizes the quantitative assessments and research needs identified during the process. Limitations in the evidence from oral poliovirus vaccine (OPV) challenge studies and other relevant data led to differences in expert assessments, indicating the need for additional data, particularly in several priority areas for research: (1) the ability of IPV‐induced immunity to prevent or reduce excretion and affect transmission, (2) the impact of waning immunity on the probability and extent of poliovirus excretion, (3) the relationship between the concentration of poliovirus excreted and infectiousness to others in different settings, and (4) the relative role of fecal‐oral versus oropharyngeal transmission. This assessment of current knowledge supports the immediate conduct of additional studies to address the gaps.  相似文献   

2.
During the last two decades, productivity research and applications have not been given adequate importance when trying to attain excellence in the management of manufacturing enterprises. Recent developments in managerial philosophies Total Quality Management and Business Process Re-engineering , manufacturing technologies Flexible Manufacturing Systems, Computer Integrated Manufacturing, etc. and Information Technology innovations have made the traditional productivity improvement techniques obsolete. This article presents a review consisting of analyses of literature on productivity and a survey of manufacturing enterprises. A five-step preview strategy on productivity is enumerated which provides a meaningful direction towards future productivity research and application. The article is concluded by briefly describing the current research that is being carried out based on the preview strategy evolved.  相似文献   

3.
America and Britain have taken a long time to accept conceptually and pragmatically the post-war economic performance of Japan and other capitalist countries. Our understanding of how to improve our production infrastructure remains inadequate. This paper addresses the critical area of manufacturing organization and restructuring production operations to offer substantial and immediate results. Most of the resources required to become a world class manufacturer are already in place in the UK and the US, yet the organization of these resources remains lacking. The purpose of this paper is to review the importance of productivity and energy conversion within an integrated manufacturing strategy. Current differences in operations management thinking that exist between  相似文献   

4.
平战结合下的公路养护多资源布局问题研究   总被引:1,自引:0,他引:1  
平战结合是突发事件应急管理的重要原则之一.以公路养护中的平时资源和应急资源的布局问题为研究对象,考虑到日常养护点的选址和资源配置要满足工作的便利性和不同养护点之间工作量的均衡性,把应急资源放置在日常养护点上,既节省管理成本又能满足及时调度的要求,建立一个多目标的混合整数规划模型同时对日常和应急2种资源进行布局,并设计了算法,最后给出了算例.  相似文献   

5.
Beliefs and the Perception of Risks and Accidents   总被引:3,自引:0,他引:3  
Identifying the causes of accidents is a necessary prerequisite for preventive action. Some research suggests however that the analysis of accidents does not only differ between experts and laymen but that it is also linked to certain characteristics inherent in the analyst and in the social group to which he belongs: beliefs, value systems, norms, experiences in common, attitudes, roles, social and technical practices, etc. Culturally determined bias seems to affect the perception of risk and the causes of accidents. This article presents a certain number of thoughts and results based upon research carried out on causal attributions of traffic accidents in The Ivory Coast (West Africa) and discusses the importance of culture in risk-taking and accident prevention. It shows in particular that fatalistic beliefs and mystical practices influence the perception of accidents and consequently incite one to take more risks and neglect safety measures.  相似文献   

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9.
Safety Investment and the Value of Life and Injury   总被引:1,自引:0,他引:1  
The requirement to reduce risk is moderated under British law by the notion of practicability or reasonable practicability. This implies that a balance should be struck, inter alia , between the costs of a risk-reducing measure and its benefits in terms of life-saving and injury avoidance. Clearly, were lives and injuries valued in monetary terms, balances and imbalances would be all the more easily identified. This paper reports on progress on the application of the Relative Utility Loss Approach to the valuation of injuries in the consumer and transportation spheres in the United Kingdom. Although the tools are as yet imperfect, striking accord is noticed between valuations of a range of serious and slight injuries obtained using three health state utility indices of disparate origin.  相似文献   

10.
期权博弈理论的方法模型分析与发展   总被引:101,自引:14,他引:87       下载免费PDF全文
安瑛晖  张维   《管理科学》2001,4(1):38-44
针对传统企业项目投资估价和决策理论方法中存在的问题 ,结合国外最新研究成果 ,对期权定价理论和博弈论在企业项目投资估价和决策中应用的新方法——期权博弈理论方法进行分析研究 ,总结归纳出期权博弈方法的一般化分析框架 ,并对一些典型的模型进行综述 ,提出进一步研究的方向  相似文献   

11.
Let G be a undirected connected graph. Given g groups each being a subset of V(G) and a number of colors, we consider how to find a subgroup of subsets such that there exists a tree interconnecting all vertices in each subset and all trees can be colored properly with given colors (no two trees sharing a common edge receive the same color); the objective is to maximize the number of subsets in the subgroup. This problem arises from the application of multicast communication in all optical networks. In this paper, we first obtain an explicit lower bound on the approximability of this problem and prove Ω(g1−ε)-inapproximability even when G is a mesh. We then propose a simple greedy algorithm that achieves performance ratio O√|E(G)|, which matches the theoretical bounds. Supported in part by the NSF of China under Grant No. 70221001 and 60373012.  相似文献   

12.
杨东峰  殷成志 《管理学报》2007,4(2):249-252
简要介绍了由国家发展和改革委员会和世界银行于2006年10月25日在北京召开的国家规划与政策的监测评估国际研讨会。对国家层面规划监测评估的基本理论、方法以及世界银行和美国、新西兰、澳大利亚等国的相关经验进行了综述。同时,给出了在会上提出的中国“十一五规划”实施的监测评估的初步框架。  相似文献   

13.
高充彦  郝辽钢 《管理学报》2010,7(1):103-110
以我国企业的中高层管理人员为对象,通过实证分析,研究期望和竞争对员工满意和忠诚度的影响,并进一步建立基于期望和竞争的员工满意与忠诚度模型。实证分析显示,员工价值低于期望对满意度评价所带来的负面影响要比员工价值高于期望所带来的正面影响大。此外,本企业的员工价值与竞争对手企业所能提供价值的比较也直接影响到满意度的高低,高层管理人员的满意度更受竞争情况的影响。对于忠诚度,高层和中低层管理人员离职倾向都显著地受到期望与竞争的影响,对2组人员来讲,竞争比期望对离职倾向的影响要更显著,而且中低层管理人员的总体离职倾向要比高层管理人员高。  相似文献   

14.
Abstract

Evaluation of mental effort under industrial conditions encounters both methodological and practical problems mainly because of lack of appropriate indices and difficulties in differentiation between body responses to physical and mental effort.

This paper presents a review of laboratory and field research from our laboratories aimed at finding objective indices for discrimination between body responses to mental and physical effort. The laboratory data show that urinary noradrenaline/adrenaline (NA/A) ratio decreases in response to mental tasks and increases in response to physical tasks. Under industrial conditions the predominating component of effort (mental or physical) evokes body response similar to that found during laboratory experiments. Re-analysis of data published in various other papers shows the same pattern of body response.

Another possible index for assessment of effort seems to be salivary cortisol which increases in response to both mental and physical tasks. Its deviations from the circadian pattern of excretion may represent a potential criterion for assessment of the emotional component of mental effort.  相似文献   

15.
Evaluation of mental effort under industrial conditions encounters both methodological and practical problems mainly because of lack of appropriate indices and difficulties in differentiation between body responses to physical and mental effort.

This paper presents a review of laboratory and field research from our laboratories aimed at finding objective indices for discrimination between body responses to mental and physical effort. The laboratory data show that urinary noradrenaline/adrenaline (NA/A) ratio decreases in response to mental tasks and increases in response to physical tasks. Under industrial conditions the predominating component of effort (mental or physical) evokes body response similar to that found during laboratory experiments. Re-analysis of data published in various other papers shows the same pattern of body response.

Another possible index for assessment of effort seems to be salivary cortisol which increases in response to both mental and physical tasks. Its deviations from the circadian pattern of excretion may represent a potential criterion for assessment of the emotional component of mental effort.  相似文献   

16.
This article presents decision-making tools for remanufacturing. The first decision-making tool was used to address inventory lot-sizing problems in a hybrid remanufacturing–manufacturing system with varying remanufacturing fraction. In this article, the new inventory lot-sizing model with variable remanufacturing lot sizes has been shown to exhibit better performance than the benchmark model with fixed remanufacturing lot sizes. The new inventory lot-sizing model is anticipated to become a valuable decision-making tool in companies that are planning to adopt remanufacturing. The second decision-making tool was applied to address a production and inventory planning problem in a remanufacturing system considering different remanufacturing policies for a given remanufacturing strategy. For a remanufacture-to-stock system with two quality remanufacturables groups four alternative policies were examined, a policy which specifies simultaneous processing utilising dedicated resources was shown to be the best policy to achieve a shorter remanufacturing cycle time. For a remanufacture-to-order system with two quality remanufacturables groups, the three relevant policies of the four alternative policies were examined, a policy which specifies sequential processing and switching between various quality remanufacturables groups was shown to be the best policy to achieve a shorter remanufacturing cycle time. The production and inventory planning simulation models in a remanufacturing system are expected to become significant decision-making tools in remanufacturing operations.  相似文献   

17.
This article discusses political and economic changes in Poland, Central and Eastern Europe emerging since the demise of the ‘closed system’ in 1989. The presentation explores the range of change, the method and the sequence of change. General lessons in economic transition as identified by Polish Finance Minister Lezak Balcerowicz are discussed. The challenges involved in macroeconomic stabilization, radical liberalization, currency convertibility, subsidy reduction and conversion of state-owned enterprises are reviewed. Despite their complexity, economic and political reforms proved necessary and inevitable. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
  流动性是市场的灵魂,金融创新的目的和结果是提高资产的流动性。2010年3月31日,证监会以促进市场流动性为目的,正式推出融资融券业务试点,并在2011年至2013年先后3次扩大中国A股市场融资融券标的股票的范围。因此,研究中国融资融券是否促进流动性并探究其内在机制具有非常重要的现实意义。         排除股指期货和股指期权等卖空机制的影响,运用面板回归方法和适合政策评估的双重差分法,分别检验2011年至2013年3次融资融券扩容对标的股票流动性的影响,并从融资和融券交易者的短期交易策略和标的股票股东结构变化两个方面探讨买空卖空机制与流动性因果关系的内在机制。         研究结果表明,融资和融券交易的双重引入降低了交易成本和价格影响,提高了标的股票的流动性。随着融资融券业务的深入开展和发展,融资融券标的股票扩容对价格影响方面的流动性的影响越来越强。融资交易者的短期动量交易策略降低了价格影响和交易成本,融券交易者的短期动量交易策略降低了价格影响,而对交易成本影响不显著。由于部分机构投资者退场,偏好短线投机炒作的中大型个体投资者入场,换手率高、流通市值低和特质波动率低等类型的标的股票组合的流动性提高更为明显。         融资融券交易提高标的股票流动性的研究结论补充了已有研究关于买空卖空机制对市场质量影响方面的实证证据,也为中国融资融券业务的发展和完善提供借鉴意义。  相似文献   

19.
本文首先讨论P3、P3e/c项目管理软件与企业管理信息系统集成的必要性和重要性,然后详细地介绍了采用RA引擎(OLE对象)技术来实现P3软件与企业管理信息系统的数据交换,以及与P3e/c交互的原理。分析P3、P3e/c在数据组织上的差异,提出解决方案。最后以实例讨论和分析了这种方法在实际系统中的应用。  相似文献   

20.
Raj Aggarwal 《决策科学》1990,21(3):588-595
This paper examines the statistical distribution of exchange rates for eight major currencies for the post-1973 floating rate period. The results show that spot rates, forward rates, and ex-post risk premia all exhibit significant, persistent, but varying deviations from normality, and that the risk premia in forward rates reflect investor preferences for skewness and investor aversion towards standard deviation and kurtosis. These results imply that foreign currency forecasting and hedging practices, mean-variance portfolio analysis, pricing of foreign currency options, and other research involving exchange rates should account for these significant deviations from normality.  相似文献   

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